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227 Views of RNA: Is RNA Unique in Its Chemical Isomer Space?

Cleaves HJ, Meringer M, Goodwin J - Astrobiology (2015)

Bottom Line: However, to date no one-pot reaction has been shown capable of yielding RNA monomers from likely prebiotically abundant starting materials, though this does not rule out the possibility that simpler, more easily prebiotically accessible nucleic acids may have preceded RNA.The resulting structures are then evaluated by using molecular descriptors typically applied in quantitative structure-property relationship (QSPR) studies and predicted physicochemical properties.We conclude that ribonucleosides may have competed with a multitude of alternative structures whose potential proto-biochemical roles and abiotic syntheses remain to be explored.

View Article: PubMed Central - PubMed

Affiliation: 1 Earth-Life Science Institute (ELSI), Tokyo Institute of Technology , Tokyo, Japan .

ABSTRACT
Ribonucleic acid (RNA) is one of the two nucleic acids used by extant biochemistry and plays a central role as the intermediary carrier of genetic information in transcription and translation. If RNA was involved in the origin of life, it should have a facile prebiotic synthesis. A wide variety of such syntheses have been explored. However, to date no one-pot reaction has been shown capable of yielding RNA monomers from likely prebiotically abundant starting materials, though this does not rule out the possibility that simpler, more easily prebiotically accessible nucleic acids may have preceded RNA. Given structural constraints, such as the ability to form complementary base pairs and a linear covalent polymer, a variety of structural isomers of RNA could potentially function as genetic platforms. By using structure-generation software, all the potential structural isomers of the ribosides (BC5H9O4, where B is nucleobase), as well as a set of simpler minimal analogues derived from them, that can potentially serve as monomeric building blocks of nucleic acid-like molecules are enumerated. Molecules are selected based on their likely stability under biochemically relevant conditions (e.g., moderate pH and temperature) and the presence of at least two functional groups allowing the monomers to be incorporated into linear polymers. The resulting structures are then evaluated by using molecular descriptors typically applied in quantitative structure-property relationship (QSPR) studies and predicted physicochemical properties. Several databases have been queried to determine whether any of the computed isomers had been synthesized previously. Very few of the molecules that emerge from this structure set have been previously described. We conclude that ribonucleosides may have competed with a multitude of alternative structures whose potential proto-biochemical roles and abiotic syntheses remain to be explored.

No MeSH data available.


The number of structures with a given number of stereocenters of the output set. Black bars: number of connectivity isomers. White bars: number of total stereoisomers.
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f6: The number of structures with a given number of stereocenters of the output set. Black bars: number of connectivity isomers. White bars: number of total stereoisomers.

Mentions: The 227 generated structural isomers yield 962 total stereoisomers. The ability of each to enable base-pairing bears consideration. The molecules in the final set each contain between zero and five stereocenters. The distribution of stereocenters is shown in Fig. 6, along with the cumulative number of stereoisomers.


227 Views of RNA: Is RNA Unique in Its Chemical Isomer Space?

Cleaves HJ, Meringer M, Goodwin J - Astrobiology (2015)

The number of structures with a given number of stereocenters of the output set. Black bars: number of connectivity isomers. White bars: number of total stereoisomers.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4523004&req=5

f6: The number of structures with a given number of stereocenters of the output set. Black bars: number of connectivity isomers. White bars: number of total stereoisomers.
Mentions: The 227 generated structural isomers yield 962 total stereoisomers. The ability of each to enable base-pairing bears consideration. The molecules in the final set each contain between zero and five stereocenters. The distribution of stereocenters is shown in Fig. 6, along with the cumulative number of stereoisomers.

Bottom Line: However, to date no one-pot reaction has been shown capable of yielding RNA monomers from likely prebiotically abundant starting materials, though this does not rule out the possibility that simpler, more easily prebiotically accessible nucleic acids may have preceded RNA.The resulting structures are then evaluated by using molecular descriptors typically applied in quantitative structure-property relationship (QSPR) studies and predicted physicochemical properties.We conclude that ribonucleosides may have competed with a multitude of alternative structures whose potential proto-biochemical roles and abiotic syntheses remain to be explored.

View Article: PubMed Central - PubMed

Affiliation: 1 Earth-Life Science Institute (ELSI), Tokyo Institute of Technology , Tokyo, Japan .

ABSTRACT
Ribonucleic acid (RNA) is one of the two nucleic acids used by extant biochemistry and plays a central role as the intermediary carrier of genetic information in transcription and translation. If RNA was involved in the origin of life, it should have a facile prebiotic synthesis. A wide variety of such syntheses have been explored. However, to date no one-pot reaction has been shown capable of yielding RNA monomers from likely prebiotically abundant starting materials, though this does not rule out the possibility that simpler, more easily prebiotically accessible nucleic acids may have preceded RNA. Given structural constraints, such as the ability to form complementary base pairs and a linear covalent polymer, a variety of structural isomers of RNA could potentially function as genetic platforms. By using structure-generation software, all the potential structural isomers of the ribosides (BC5H9O4, where B is nucleobase), as well as a set of simpler minimal analogues derived from them, that can potentially serve as monomeric building blocks of nucleic acid-like molecules are enumerated. Molecules are selected based on their likely stability under biochemically relevant conditions (e.g., moderate pH and temperature) and the presence of at least two functional groups allowing the monomers to be incorporated into linear polymers. The resulting structures are then evaluated by using molecular descriptors typically applied in quantitative structure-property relationship (QSPR) studies and predicted physicochemical properties. Several databases have been queried to determine whether any of the computed isomers had been synthesized previously. Very few of the molecules that emerge from this structure set have been previously described. We conclude that ribonucleosides may have competed with a multitude of alternative structures whose potential proto-biochemical roles and abiotic syntheses remain to be explored.

No MeSH data available.